/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.dubbo.config.spring.beans.factory.config;

import org.springframework.beans.factory.config.YamlProcessor;
import org.springframework.core.env.MapPropertySource;
import org.springframework.core.env.PropertySource;
import org.springframework.core.io.support.EncodedResource;
import org.springframework.core.io.support.PropertySourceFactory;
import org.yaml.snakeyaml.DumperOptions;
import org.yaml.snakeyaml.Yaml;
import org.yaml.snakeyaml.nodes.Tag;
import org.yaml.snakeyaml.representer.Representer;
import org.yaml.snakeyaml.resolver.Resolver;

import java.io.IOException;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Properties;
import java.util.regex.Pattern;

/**
 * YAML {@link PropertySourceFactory} implementation, some source code is copied Spring Boot
 * org.springframework.boot.env.YamlPropertySourceLoader , see {@link #createYaml()} and {@link
 * #process()}
 *
 * @since 2.6.5
 */
public class YamlPropertySourceFactory extends YamlProcessor implements PropertySourceFactory {

  @Override
  public PropertySource<?> createPropertySource(String name, EncodedResource resource)
      throws IOException {
    setResources(resource.getResource());
    return new MapPropertySource(name, process());
  }

  @Override
  protected Yaml createYaml() {
    return new Yaml(new StrictMapAppenderConstructor(), new Representer(),
        new DumperOptions(), new Resolver() {
      @Override
      public void addImplicitResolver(Tag tag, Pattern regexp,
          String first) {
        if (tag == Tag.TIMESTAMP) {
          return;
        }
        super.addImplicitResolver(tag, regexp, first);
      }
    });
  }

  public Map<String, Object> process() {
    final Map<String, Object> result = new LinkedHashMap<String, Object>();
    process(new MatchCallback() {
      @Override
      public void process(Properties properties, Map<String, Object> map) {
        result.putAll(getFlattenedMap(map));
      }
    });
    return result;
  }

}
